PROCESSING METHOD FOR PIP DERIVED CMC ARTICLE
A disclosed method of forming a ceramic article includes forming a pre-ceramic polymer article within a mold tool, and performing a first pyrolizing step on the initial pre-ceramic polymer article to form a ceramic article. The method further includes performing at least one pre-heat treatment polymer infiltration and pyrolizing (PIP) cycle on the ceramic article and an initial heat treatment cycle of the ceramic article after the at least one pre-heat treatment PIP cycle. Subsequent PIP cycles and heat treatment cycles are performed in combination to form a ceramic article including a desired density.
1 . A method of forming a ceramic article comprising:
forming a pre-ceramic polymer article within a mold tool;
performing a first pyrolizing step on the pre-ceramic polymer article to form a ceramic article;
performing at least one pre-heat treatment polymer infiltration and pyrolizing (PIP) cycle on the ceramic article;
performing an initial heat treatment cycle of the ceramic article after the at least one pre-heat treatment PIP cycle;
performing at least one post-heat treatment PIP cycle after the at least one initial heat treatment process; and
performing at least one heat treatment cycle after the at least one post-heat treatment PIP cycle.
2 . The method as recited in claim 1 , wherein the at least one pre-heat treatment PIP cycle on the ceramic article comprises at least two (2) PIP cycles.
3 . The method as recited in claim 1 , wherein the at least one pre-heat treatment PIP cycle on the ceramic article comprises at least six (6) PIP cycles.
4 . The method as recited in claim 1 , wherein the at least one post-heat treatment PIP cycle comprises at least two (2) PIP cycles.
5 . The method as recited in claim 1 , including performing the at least one heat treatment cycle after at least one (1) post-heat treatment PIP cycles.
6 . The method as recited in claim 5 , including repeating both the post heat treatment PIP cycle after one heat treatment cycle for between two (2) and eight (8) iterations.
7 . The method as recited in claim 5 , including performing the post heat treatment PIP cycle two (2) times after a one heat treatment cycle for between two (2) and eight (8) iterations.
8 . The method as recited in claim 1 , wherein the heat treatment cycle comprises exposing the ceramic article to a temperature between about 1200° C. and 1600° C.
9 . The method as recited in claim 1 , wherein the PIP cycle comprises heating the ceramic article to temperature between about 900° C. and 1100° C. in an inert environment.
10 . A method of forming a ceramic article comprising;
forming a pre-ceramic polymer article within a mold tool;
performing a first pyrolizing step on the pre-ceramic polymer article to form a ceramic article;
performing at least one pre-heat treatment polymer infiltration and pyrolizing (PIP) cycle on the ceramic article;
performing an initial heat treatment of the ceramic article after the at least one pre-heat treatment PIP cycle; and
performing a densification step after the initial heat treatment including at least one PIP cycle followed by a heat treatment process.
11 . The method as recited in claim 10 , including repeating the densification step for at least two (2) iterations.
12 . The method as recited in claim 10 , including repeating the densification step for between two (2) and eight (8) iterations.
13 . The method as recited in claim 10 , wherein the at least one pre-heat treatment PIP cycle comprises between two (2) and eight (8) cycles.
14 . The method as recited in claim 10 , wherein the densification step comprises at least two (2) PIP cycles followed by the heat treatment process.
15 . The method as recited in claim 10 , wherein the heat treatment cycle comprises exposing the ceramic article to a temperature between about 1200° C. and 1600° C.
16 . The method as recited in claim 10 , wherein the PIP cycle comprises heating the ceramic article to a temperature between about 900° C. and 1100° C. in an inert environment.